The roadside test could justify further investigation, including more elaborate testing at a police station.

Justice Minister Jody Wilson-Raybould says she has “every expectation” the new law will be challenged in the courts, but added she is confident it is consistent with the Charter of Rights and Freedoms.

She says the intent is to save lives is an “incredibly justifiable purpose.”

The Canadian Civil Liberties Association has expressed concern that mandatory alcohol screening will unfairly affect racial minorities who are disproportionately singled out by police for traffic stops.

Organized Crime Reduction Minister Bill Blair said if a police stop were motivated by bias, it would be unlawful and contrary to the charter, and therefore a breath test would be inadmissible in court.

Research suggests that up to half of drivers with a blood alcohol concentration above the legal limit are not detected at roadside check stops.